LOANS AND LEASES (Schedule of Balances by Portfolio Class, Based on Impairment Method) (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Jun. 30, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Dec. 31, 2017
Total Loans Individually Evaluated for Impairment	$ 36,627		$ 31,300
Ending ALLL Attributable to Loans Individually Evaluated for Impairment	2,737		262
Total Loans Collectively Evaluated for Impairment	4,119,204		3,893,012
Ending ALLL Attributable to Loans Collectively Evaluated for Impairment	38,843		38,242
Total Loans	4,155,831		3,924,312
Total Ending ALLL	41,580	$ 39,791	38,504	$ 37,293	$ 38,066	$ 36,440
Residential Portfolio Segment [Member] | Primary Residential Mortgages [Member]
Total Loans Individually Evaluated for Impairment	7,238		9,518
Ending ALLL Attributable to Loans Individually Evaluated for Impairment	237		262
Total Loans Collectively Evaluated for Impairment	579,166		591,373
Ending ALLL Attributable to Loans Collectively Evaluated for Impairment	2,252		3,244
Total Loans	586,404		600,891
Total Ending ALLL	2,489	3,057	3,506	4,132	4,382	4,085
Residential Portfolio Segment [Member] | Home Equity Lines of Credit [Member]
Total Loans Individually Evaluated for Impairment	3		255
Total Loans Collectively Evaluated for Impairment	58,422		61,936
Ending ALLL Attributable to Loans Collectively Evaluated for Impairment	145		164
Total Loans	58,425		62,191
Total Ending ALLL	145	155	164	197	190	221
Residential Portfolio Segment [Member] | Multifamily Property [Member]
Total Loans Individually Evaluated for Impairment			1,262
Total Loans Collectively Evaluated for Impairment	1,197,093		1,134,543
Ending ALLL Attributable to Loans Collectively Evaluated for Impairment	6,235		5,959
Total Loans	1,197,093		1,135,805
Total Ending ALLL	6,235	5,744	5,959	7,655	8,259	10,007
Residential Portfolio Segment [Member] | Junior Lien [Member]
Total Loans Individually Evaluated for Impairment	24		36
Total Loans Collectively Evaluated for Impairment	7,039		7,382
Ending ALLL Attributable to Loans Collectively Evaluated for Impairment	15		15
Total Loans	7,063		7,418
Total Ending ALLL	15	15	15	16	17	12
Commercial Real Estate Portfolio Segment [Member] | Owner Occupied Property [Member]
Total Loans Individually Evaluated for Impairment	395		1,574
Total Loans Collectively Evaluated for Impairment	258,168		259,619
Ending ALLL Attributable to Loans Collectively Evaluated for Impairment	2,272		2,614
Total Loans	258,563		261,193
Total Ending ALLL	2,272	2,497	2,614	2,387	2,525	2,385
Commercial Real Estate Portfolio Segment [Member] | Investment Property [Member]
Total Loans Individually Evaluated for Impairment	22,676		18,655
Ending ALLL Attributable to Loans Individually Evaluated for Impairment	1,000
Total Loans Collectively Evaluated for Impairment	1,022,054		983,263
Ending ALLL Attributable to Loans Collectively Evaluated for Impairment	14,745		14,248
Total Loans	1,044,730		1,001,918
Total Ending ALLL	15,745	14,650	14,248	12,791	13,659	11,933
Commercial Portfolio Segment [Member] | Construction Loans [Member]
Total Loans Collectively Evaluated for Impairment	4,579		86
Ending ALLL Attributable to Loans Collectively Evaluated for Impairment	24		1
Total Loans	4,579		86
Total Ending ALLL	24	1	1	1	1	1
Consumer and Other Loans [Member]
Total Loans Collectively Evaluated for Impairment	57,271		65,180
Ending ALLL Attributable to Loans Collectively Evaluated for Impairment	315		384
Total Loans	57,271		65,180
Total Ending ALLL	315	319	384	378	364	349
Commercial and Industrial Sector [Member] | Commercial Portfolio Segment [Member]
Total Loans Individually Evaluated for Impairment	6,291
Ending ALLL Attributable to Loans Individually Evaluated for Impairment	1,500
Total Loans Collectively Evaluated for Impairment	698,435		616,838
Ending ALLL Attributable to Loans Collectively Evaluated for Impairment	10,405		9,839
Total Loans	704,726		616,838
Total Ending ALLL	11,905	11,463	9,839	8,185	7,356	$ 6,563
Lease Financing [Member]
Total Loans Collectively Evaluated for Impairment	233,918		172,643
Ending ALLL Attributable to Loans Collectively Evaluated for Impairment	2,396		1,772
Total Loans	233,918		172,643
Total Ending ALLL	2,396		1,772
Agricultural Sector [Member]
Total Loans Collectively Evaluated for Impairment	3,059		149
Ending ALLL Attributable to Loans Collectively Evaluated for Impairment	39		2
Total Loans	3,059		149
Total Ending ALLL	$ 39	$ 2	$ 2	$ 2	$ 2